Developing combat aircraft is a complex task and sometimes you can take advantage of an existing plane to develop one for another service/task. An extreme example is the huge Flanker family....
They not only invented gunpowder but also the gun. A photograph in the magazine Technology & Culture nearly halve a century ago showed a bas-relieve in a chapel just south of the Yangtze-...
Ask China. It might cooperate with ESA and Russia.
The UK ban doesn't contain all the airports affected by the US ban but added a few others. WWHHYY???
That treaty was signed by the US installed puppet regime and repudiated when Cuba became independent in 1959.